The Phase I study demonstrated the feasibility that highly oriented PEEK and carbon-fiber-reinforced PEEK (CFR-PEEK) could be engineered as surface phosphonylated dental implants and these implants could be microtextured to enhance osseointegration. In the Phase I study, surface-phosphonylated and microtextured rods composed of solid-state oriented PEEK and CRF-PEEK were implanted transcortically in edentulous mandibles in goats and were assessed at 12 weeks for osseointegration. The results indicated (1) solid-state orientation of PEEK increased modulus; (2) phosphonylation of PEEK promoted osseointegration; and (3) osseointegration was further enhanced by surface microtexturing and immobilizing calcium to the phosphonylated PEEK surface. These results and additional studies at Poly-Med on PEEK clearly indicate several polymer engineering options can produce an optimum endosteal dental implant (EDI). Therefore, the options for the Phase II study will include solid-state orientation, fiber-ultradrawing, surface phosphonylation, fiber reinforcement, and self-reinforcement of PEEK. The ultimate goal for the Phase II study will be to engineer a novel cementless, EDI that will not have the biological and biomechanical deficiencies of metallic EDIs. Phase II objectives are consistent with this goal and will be to (1) use surface phosphonylation, solid-state orientation, and radiochemical sterilization, for optimized preparation of solid-state oriented PEEK, CFR-PEEK composites, and fiber self- reinforced PEEK composites; (2) design and construct three types of EDIs, implant in a dog model, quantitate biological responses intraorally, and compare to a commercial titanium EDI; (3) select one type of PEEK-based EDI for optimizing and finalizing plans for Phase III; and (4) identify a marketing partner for collaboration for planning and executing Phase III. Phase III efforts will address (1) final development and scale-up of the selected EDI and (2) conducting relevant studies to meet regulatory approval. PROPOSED COMMERCIAL APPLICATION: Phase II results will provide critical data for finalizing the selected endosteal implant for pilot-scale production and executing the safety and clinical studies in Phase III. Successful completion of Phase III will lead to the first introduction of a cementless, polymeric EDI for anchoring artificial teeth and bridging to natural ones. This technology will also be extended to several orthopedic applications.